A conventional daisy-chaining storage system that includes a host computer, and multiple sets of daisy-chaining storage devices coupled to the host computer, where each set of the daisy-chaining storage devices includes a plurality of storage devices serially coupled in a daisy chain. The host computer may include a connection module supporting, for example, serial attached SCSI (SAS) wide port interface. Each storage device may include, for example, a plurality of hard disk drives (HDDs), and two expanders that support the SAS wide port interface, that are coupled to the HDDs, and that are coupled to the expanders of an adjacent storage device, or to the connection module of the host computers using two SAS cables.
However, in a conventional firmware update process for the expanders of the storage devices, since the host computer has no information of connection relationships among multiple connection ports thereof and the expanders, in order to ensure that a firmware update can be completed successfully for each expander, only one of all those expanders that are connected to the same host is permitted to perform the firmware update at one time even if the expanders may be connected to different connection ports, and the firmware update for the next expander is permitted only when the currently performed firmware update is completed. Such a process may require much time for completing the firmware updates on all expanders, resulting in inefficiency, and any abnormality that occurs during an update of any one of the expanders may cause a serious delay in the overall updating process or incompletion of the firmware updates for other expanders.